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SENUBIO group > Environmental safety
Line 1. Study of environmental raditaton. Radon and its descendants.
Initially, natural radiation sources were considered as environmental radiation sources to which everyone was exposed and was not necessary to control. All control efforts, based on the recommendations of the International Commission on Radiological Protection (ICRP) made from advances in the international community, are also dedicated to artificial sources. That is, to dose control as it is received from the action of man. However, it was discovered that the most important contribution of the total annual dose received by the public is due to natural radiation, and specifically to the inhalation of the descendants of the short life of radon. This fact increased the sensitivity of the scientific community, researchers and society in general.
Radon, a noble gas that comes from the radioactive decay of uranium and radium has a half-life of 3.08 days. During this period, it is transported from its origin source (soil, water, and building materials) to spread in the air, for which it has a great affinity. The hazard of radon is due to its descendants, Polonium-218 and Polonium-214. Both solid elements that adhere to aerosols and other particles present in the environment. During the breathing process, both radon and its descendants are inhaled by the human body and, once inside, these particles are deposited on the respiratory system. During the decay, they continue emitting alpha particles that hurt lung tissue causing an important biological damage. In 1986, the World Health Organization (WHO) classified radon as a carcinogen. From this derives the need for the development of internal dosimetry models.
In 1996 the Council of the European Union (CEU) published a directive with the basic safety standards for the workers and members of general public of health protection against damage due to ionizing radiation. There was a particular chapter dedicated to natural radiation sources. Specifically, it forced EU members to identify those activities where workers and members of the general public may have a significant increase in exposure due to the inhalation of descendants of Radon, Thorium and gamma radiation that cannot be underestimated according to the radiological protection point of view.
Moreover, regarding to drinking water, the CEC recommended, in 2001, to carry out measurements of Radon level in groundwater located in different geological areas that were intended for human consumption. The main objective was to determine the scale and nature of the exposures to which the consuming population could be exposed.
Regarding Spanish legislation, recently, the CSN (Consejo de Seguridad Nuclear) has published the Instruction IS-33 that includes the radiological criteria for natural radiation exposure (CSN, 2012). It determines the reference limits for workers in terms of effective doses and radon concentration. Additionally, it establishes the obligation to take corrective measures and monitoring devices in case of exceeding limits.
The study of natural radiation sources as radon and its descendants is raised in this I+D+I research. Likewise it is necessary to investigate and provide solutions according to radon issue. Therefore, the development of internal radon dosimetry models and its descendants is very important.
This research allows the in-situ and real-time characterization of ionizing radiation. Among the applications of this study, there is an analysis of radon levels as well as the proposal of mitigation solutions in different workplaces such as the ceramic industry, waste water pre-treatment plants, and water treatment plant. In addition, it is important to characterize the ionizing radiation in other industrial environments. According the needed detectors, Radon levels in air and water can be determined in situ, and the equilibrium factor can be determined for the subsequent calculation of the effective dose of the workers in a more exact way.
Line 2. Development of equations and algorithms for the calculation of the dispersion of atmospheric pollutants
Study and development of equations and algorithms for the calculation of the dispersion of atmospheric pollutants in real physical systems. In this line, a study and verification of the operation of the different codes for the calculation of atmospheric behavior is carried out and for the dispersion processes that take place inside it. Several are the models with which we are currently working. Mainly two points stand out. On one hand, the study of the dispersion of pollutants from point sources, adapting the model to the environment in which the source is located, both due to its climatic and orographic conditions. On the other hand the adoption of criteria for determining the appropriate chimney height to optimize the dispersion of the emission.
 
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